Fix #1822 - support go-langserver lsp.

ale_linters/go/golangserver.vim

@@ -0,0 +1,28 @@
+" Author: Horacio Sanson <https://github.com/hsanson>
+" Description: Support for go-langserver https://github.com/sourcegraph/go-langserver
+
+call ale#Set('go_langserver_executable', 'go-langserver')
+call ale#Set('go_langserver_options', '')
+
+function! ale_linters#go#golangserver#GetCommand(buffer) abort
+    let l:executable = [ale#Escape(ale#Var(a:buffer, 'go_langserver_executable'))]
+    let l:options = ale#Var(a:buffer, 'go_langserver_options')
+    let l:options = substitute(l:options, '-gocodecompletion', '', 'g')
+    let l:options = filter(split(l:options, ' '), 'empty(v:val) != 1')
+
+    if(ale#Var(a:buffer, 'completion_enabled') == 1)
+      call add(l:options, '-gocodecompletion')
+    endif
+
+    let l:options = uniq(sort(l:options))
+
+    return join(extend(l:executable, l:options), ' ')
+endfunction
+
+call ale#linter#Define('go', {
+\   'name': 'golangserver',
+\   'lsp': 'stdio',
+\   'executable_callback': ale#VarFunc('go_langserver_executable'),
+\   'command_callback': 'ale_linters#go#golangserver#GetCommand',
+\   'project_root_callback': 'ale#go#FindProjectRoot',
+\})